This invention relates generally to injection mold apparatuses and, more specifically, to injection mold apparatuses having automated article removal equipment.
The manufacture of small plastic articles is often most efficiently accomplished by use of an injection mold apparatus capable of concurrently molding a large number of the plastic articles.
Virtually all such injection mold apparatuses comprise some form of article removal equipment capable of automatically removing the finished plastic articles from the mold.
In the manufacture of certain plastic articles, it is highly advantageous to cool the finished plastic article upon their removal from the mold. U.S. Pat. No. 5,447,426, discloses an injection mold apparatus having equipment which automatically removes the finished plastic articles from the mold and incorporates a cooling system for rapidly cooling those finished plastic parts. The cooling of the plastic articles in the removal equipment is advantageous to the user because the cooling of the plastic articles is thereby rapidly and efficiently accomplished.
Unfortunately, the device taught in the ""426 patent is not wholly satisfactory. The device employs a take-off plate having a plurality of article acceptors to accept the plastic articles from the mold apparatus and to transfer them away from the mold apparatus. Each of these article acceptors is rearwardly tapered. A vacuum is used at the rear portion of each acceptor to draw the finished plastic article into the acceptor. This method of drawing the finished articles into the acceptors limits the applicability of the method to only a certain range of taper angles within the acceptors. Moreover, cooling within the acceptors tends to be non-uniform since the sidewalls of each article are in contact with the cooled interior sidewall surface of each acceptor before the end portion of each article is fully drawn into contact with the cooled interior bottom wall surface of the acceptor. Still further, the use of vacuum equipment in the take-off plates requires that the take-off plates be cumbersome, heavy and difficult to rapidly move. It also necessitates that each take-off plate carry complex article ejection equipment to eject the articles from the acceptors after the articles are cooled.
Accordingly, there is a need for an ejection mold apparatus having the capability to automatically remove and cool finished molded articles which avoids the aforementioned problems in the prior art.
The invention satisfies this need. The invention is an apparatus useful in the manufacture of molded articles. The apparatus comprises a mold for making the molded articles, a take off plate (termed herein a xe2x80x9cfirst carrying devicexe2x80x9d) for transferring molded articles from the mold and a second similar take off plate (xe2x80x9csecond carrying devicexe2x80x9d) for transferring the articles from the mold.
The mold has a first portion and an opposed second portion. The first portion comprises an array of N mold cavities. The second portion comprises an array of N mandrels. Each of the mandrels are aligned with one of the mold cavities. The first portion and the second portion of the mold are movable with respect to one another between (i) a closed position wherein the first portion and the second portion are in abutment with one another and the mold cavities are each enclosed, (ii) a fully open position wherein the first portion and the second portion are spaced apart from one another by a distance dfo and (iii) a first intermediate open position wherein the first portion and the second portion are spaced apart from one another by a distance d1, d1, being less than dfo. Thus, when the first mold portion and the second mold portion are in the closed mold position, molded articles can be made within the mold cavities. On the other hand, when the first portion and the second portion of the mold are in one of the open positions, each of the molded articles formed within the mold cavities can be retained on one of the mandrels.
The first carrying device comprises a first array of N article acceptors. Each of the article acceptors is sized and dimensioned to accept and retain a molded article from one of the mandrels. Each of the article acceptors within this first array has an open forward end and a rearward end. Each of the forward ends of the article acceptors within the first array is disposed within a first article acceptor plane.
The first carrying device is movable between (i) an extended first carrying device position wherein the first carrying device is disposed between the first portion and the second portion of the mold when the first portion and the second portion are in the fully open position and each of the first article acceptors is aligned with a mandrel within the second portion of the mold and (ii) a retracted first carrying device position wherein the first carrying device is not disposed between the first portion of the mold and the second portion of the mold.
Like the first carrying device, the second carrying device comprises a second array of N article acceptors. Each of the articles acceptors is sized and dimensioned to accept and retain a molded article from one of the mandrels. Each of the article acceptors within the second array has an open forward end and a rearward end. Each of the forward ends of the article acceptors within the second array is disposed in a second article acceptor plane.
The second carrying device is movable between (i) an extended second carrying device position wherein the second carrying device is disposed between the first portion of the mold and the second portion of the mold when the first portion and the second portion are in the fully open position and each of the second article acceptors is aligned with a mandrel within the second portion of the mold and (ii) a retracted second carrying device position wherein the second carrying device is not disposed between the first portion of the mold and the second portion of the mold.
Preferably, but optionally, each of the article acceptors is capable of being internally cooled, such as by the internal flowing of a cooling liquid.